Improvement in cupola and other melting and smelting-fuhnaces



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JOHN-ABSTERD-AM, OF NEW YORK, Nt Y. Letters'PatentNo. 86,795, `dated Februar/ry 9, 186.9.

IMPROVEMENT .IN C'CTPOLA AITDV QTHER MELTING AND SMELTING-FURNACES.

The Schedule referred to' in these Letters Patent and making part of the same.

To all whom 'it ma/y concern:

Be it known ,that I, JOHN ABSTERDAM, of the city, county, and State of New York, have invented a neW and useful Improved Furnace for theManufact-ure of Steel, Iron, and other Metals; andI do hereby declare the following to be a full, clear, and exact description thereof-sufficient to enable those skilled in the art to which my invention appertains, to fully understand the same, reference .being made to the accompanying draw-l ings, forming part of my specilication.

TheV nature of my invention consists in constructing a. double cupola-furnace, by constructing two or more furnaces, one within the other, formelting metals, but more particularly intended for making cast-steel, or melting blister and scrap-steel, and melting wroughtiron'into steel. y, f

Y Figure l represents a longitudinal vertical section in perspective of my furnace.

l Figure L is a transverse Vsection of the same, through the line y ly-of tig. l.

Figure 3 represents a longitudinal vertical section of a furnaceconstructed according to my invention, and suspended. on trunnions.

Figure 4 is a cross-section of an oblong furnace, made according to my invention.

e Similar letters of reference'indcate corresponding parts inthe several gures.

A is the outer furnace, and

R is the interior thereof'.

C is the inner furnace, and

H represents the interior of the same.

-E E are partition-Walls between `the inner furnace C and outer wall A, dividing the space into separate com? partments, or chambers, composing the furnaces.

The furnaces are built upon an Viron bottom or bedplate, B. l y

The 4outer furnace is cased with metalli, and the top of the furnace is covered by an iron casing, I, having a tire-lining, x, on the inside.

J is the smoke-due, or outlet of the furnaces, which, in lig. 1, also answers as a mouth for charging the same.

The bridge or tap-hole` of the inner furnace is at F, and F is the spout for the same.

'l is the false bottom or pivoted door of the inner furnace, 'which is made to open and closefat pleasure.

N 'represents the wind-box, surrounding the base of the outer Wall, and

O is the annular' channel in the same, for the admissionof the blast.

S is the cover to the outer furnace in iig. 3, and d is a cover of the mouth of the inner furnace in 'said figure, which may be also used to close the mouth o f the inner furnace in fig. l.

'The cover d is pressed down by means of a screwbolt, c, (iig. 3,) when the furnace is made to vswing around its trumiions.

In order'to set my furnace irl-operation, I commenceV by closing the pivoted bottom T, and the openings e e, in the inner and outer furnaces respectively.

I then introduce moulding-sand, and make a bottom -of this material over the false bottom T, and the iron the bridge F, and through the blast-holes e e, after hav- 5 ing removed the plugs p p.

When the inner furnace is sufliciently beated,l withdraw the fuel from H, through the bridge F, if required, and immediately close up 'the bridge with sand in the usual manner.4

The metal to be melted is now introduced into the inner furnace H, and I close the month of said furnace, if required,-`with a refractory cover. More fuel is also placed in the compartments D D, through openings k k, which are immediately closed by the covers Z l.

The blast is now applied, from any desired blower, to the outer furnace, and enters the tuyereholes P I?, into the channel or chamber O o f the Wind-box N, and through the holesi 'tinto' the fuel in the compartments D D, the smoke escaping through the flue or mouth' J. Y rIhe metal contained in the chamber H, is melted by the admission of caloric through .the wall C, as the same is brought to av white heat, suiiicient to melt the metals contained therein.

After the metal is melted, (which is ascertained by passing down an iron bar through one 'of the holes lc, or through the mouth of the outer furnace,) I then draw it orf, by tapping the bridge F, and receive, in'a ladle, the molten metal, which runs out through the spout F.

Now,`if another charge of metal is immediately required, the same is put-into the .inner furnace at once, as soon as the metal therein contained is drawn off. If necessary, at this point, the fires in the. furnaces may be replenished by fuel, supplied through the holes lc Je, .and I continue the operation of blowing and melting, as above described. e I

But as this furnace is particularly intended to'melt wrought-iron into steel, lI will describe the operation, which is as follows, viz: A

I commence by cutting the Wrought-iron into suitable pieces, with shears or other cutting-tools.

The iron thus cut, is introduced into an air-furnace,-4 or any other conveniant furnace, and with the iron I mix charcoal, coke, wood, or peat, and even coal, if tolerablyfree from sulphur or phosphorus,

The iron is now submitted to a red heat; and is thus made to combine with carbon from the fuel, whereby the iron becomes to some degree carbonized.

I next introduce the heated wrought-iron into the inner furnace with a pair of tongs, and Irintroduce also a required quantity of powdered charcoal into the said furnace, together with pieces of heated iron; also, some scrap-steel, which, melting rst, facilitates the melting \f the iron. A suitable quantity of flux is also introluced, which further facilitates the operation, always following the rule and practice now established iii-malring cast-steel.

.But when a cheapquality of steel is required, I prcceed as follows:

After having prepared the furnaces, as at first described, I introduce, into the inner furnace H, any required quantity of pig-iron in pieces, having previously `heated the same to a red or white heat in another' furnace.

When the pig-iron is melted, I introduce" into the same, suitable pieces of wrought-iron, heated red hot, as before mentioned, and continue thus to introduce a few pieces at a time, until a sufficient quantity is added.

This fact is ascertained by continued practice, or by testing the metal from time to time, by the introduction ot' a'scoop, made for the purpose, into the molten met-al, and drawing out a sample of the same, which is to be cast into a small ingot, reheated, and then hammei-ed into the shape deemed requisite by the operator.

According to the degreeof carbon which is desired in the moltenmetal, either cast or wrought-filon is added until the result is obtained as desired.

Afterward, the molten metal is drawn off from the furnace, as before mentioned, and the fluidsteel is cast into moulds of suitable shape and size, according to the' v oblong form. Other forms, however, would answefthe purpose, but not so conveniently, nor wouldthey be so durable or so solid aswhen built in cylindrical form.

The walls of the outer furnace may be built of ordinary arch-brick, as they are braced by an iron casing, but the Wall C .G'of the inner furnace, I make in segments or sections, made to interlock, one with another, so as to constitute a self-sustaining structure.

In order to build the inner furnace very strong and durable, I brace the same'with partition-walls, as no metallic casing could be used here as on the outer furnace, because of the extreme heat when the fires are burning.

Many advantages may be enumerated concerning thisinvention, but it will be sufiicient, perhaps, to mention only the following, viz i As steel cannot well be melted when exposed to the action of the blast, it has been the plactice, hitherto, to melt it in crucibles, which can only be done in small, separate quantities, entailing a great expenditure, both for the large number of crucibles required, and for the many workmen necessary to attend them. All this is done in order that the metal may be melted out of contact'iwith the atmosphere, while, in my furnace, I am able to meit steel in large quantities, according to the capacity of the furnace.

l have also the advantage of preserving the heat after each successive operation, by charging the inner furnace anew as soon as its molten contents have been withdrawn. v

The inner furnace retains its heat, as it is not exposed to: the cold atmosphere, as', are crucibles every time they are removed from the fire.

And as this furnace is intended to be used in the melting of wrought-iron rails into steel ingots, bythe operation last described, itis of the utmost importance to build a furnace of large dimensions, which can be done when constructed according to the plan of my double cupola-furnace.

Another advantage is, that I can melt Bessemer old steel rails and otherscrap, in my double cupola-furnace,

as well as it can be done on a small scale in acrucible.

Hitherto, there has been no use for Bessemer steel rails when replaced by new ones, as that kind of steel of which they are madel can be welded only withgreat 'difliculty, and can hardly'be melted in the furnaces now in use.

Still Vanother great advantage is, that old iron rails, now generally sold for scrap, can be melted in my double furnace by the addition of a suflicient amount of carbon in the process of melting, and then cast into steel ingots, ready for rolling into steel rails. Y

I will here state that should it be required, I can also mell pig-iron in the compartments D of the outer furnace, the same as any other cupola new used, while steel is being melted in the inner furnace. In that case,

' I provide a bridge, F, and spout, F', to each separate compartment of the said outer furnace, for drawing off the molten metal contained therein.

' The walls of the inner furnace are built of refractory material, similar to that of which fire-brick and crucibles are now made.

I do not confine my invention rto building the furnace of a particular form or shape, as long as the same principle is maintained.

Having thus described my invention` t What I claim as new, and desire tosccure by Letters Patent, is y 1. The double cupola-furnace, built by constructing two or .more furnaces, one within the other, substantially as herein described.

2. The compartments D D between the inner and outer walls AC, separated from each other by partitions E E, substantially as herein described.

3 The Wind-box N, surrounding the base of the furnace, and having the air-channel O, which communicates with the space Hg, by means of holes t', and with theouter air by means of holes P I, and other openings, which may be plugged up, substantially as and for the purpose herein set forth. v

4. The openings k k in the top, I, opposite the openings e e in the bottomplate B, both provided with pivoted covers l, all substantially as and for the purposes herein set forth.

JOHN ABSTERDAM.

Witnesses: i

Grao..v W. Ro'rnwELL, JACOB F. HENRY. 

